HemodynamicsHemodynamicsHyperemia and CongestionHyperemia and Congestion

Dr.CSBR.Prasad, M.D.

Hyperemia and Congestion Hyperemia and Congestion

Both are vascular events

Hyperemia and Congestion Hyperemia and Congestion

• Both indicate a local increased volume of blood in a particular tissue.

• There is increased vascular volume • Hyperemia is an active process - arteriolar

dilation – arterial side• Congestion is a passive process -

impaired outflow – venous side - may be systemic / local

HyperemiaHyperemia CongestionCongestion

Blood volume Increased Increased

Vascular volume Increased Increased

Mechanism Active – chemicals

Passive – stagnation

Vascular compartment Arterial side Venous side

Site Usually local Local / systemic

Hydrostatic pressure is increased in both the conditions, hence

Hyperemia and congestion are always associated with edema

Hyperemia and CongestionHyperemia and Congestion

Conjunctival hyperemia

• Inflammations – conjunctivitis• Hypercalcemia• Hyperparathyroidism• Ataxia – telangiectasia (if the

vessels are tortuous)

Conjunctival hyperemia - causesConjunctival hyperemia - causes

Sturge-Weber SyndromeSturge-Weber Syndrome

Blanching (circle)Blanching (circle)

CongestionCongestion• Distension of blood vessels• May be an active or passive process• Reversible condition

Left-sided cardiac failure

Causes:

• 1. Systemic hypertension (most common cause).

• 2. Ischemic heart disease.

• 3. Mitral or aortic valve disease.

• 4. Primary myocardial disease.

Left-sided cardiac failure Clinical presentation

1. Due to obstruction to pulmonary vascular out-flow there is pulmonary congestion and edema.

2. Reduction of renal perfusion causes:

(i) Salt and water retention (ii) Ischemic acute tubular necrosis

(iii) Impairment of waste excretion causing azotemia.

3. Reduced perfusion of central nervous system causes hypoxic encephalopathy (irritability to coma).

Right-sided cardiac failureCauses:

1. Most common cause is the left ventricular failure, causing pulmonary congestion and raised pulmonary arterial pressure.

2. Intrinsic disease of lungs and pulmonary vasculature causing obstruction to right ventricular out-flow (cor pulmonale).

3. Pulmonary or tricuspid valve disease.

4. Congenital heart disease in which there is left-to-right shunt.

Example: (i) Patent foramen ovale ; (ii) Patent ductus arterisus and (iii) Interventricular septal defect.

Other causes:

i) Extracardiac circulatory failure. Example: Haemorrhage ; vasovagal syncope etc.

ii) Impaired atrial filling by external compression. Example: Constrictive pericarditis.

Right-sided cardiac failure Clinical presentation

1. Congestion and edema of portal and dependent peripheral sites

(Eg: feet, ankle, sacrum) and effusions in pleura and peritoneum (ascites).

2. Hepatomagaly - Centrilobular congestion and atrophy of central hepatocytes (nutmeg liver)

3. Congestive splenomegaly with sinusoidal dilation, focal hemorrhage followed by hemosiderosis and fibrosis.

4. Renal congestion causes acute hypoxic tubular necrosis.

Normal liverNormal liver

Normal liverNormal liver

CVC liver -- GrossCVC liver -- Gross

In chronic passive congestion of the liver (nutmeg liver)

the central regions of the hepatic lobules are grossly red-brown and slightly depressed (owing to a loss of cells) and are accentuated against the surrounding zones of uncongested tan liver (nutmeg liver)

CVC – LiverCVC – Liver

‘Starry sky’ appearance

in US

Nut meg liver

Nut megNut meg

• Centrilobular necrosis with loss of hepatocytes dropout and

• Hemorrhage, including hemosiderin-laden macrophages

• Hepatic fibrosis [In severe, long-standing hepatic congestion there may even be grossly evident hepatic fibrosis (cardiac cirrhosis)]

CVC liver -- microscopyCVC liver -- microscopy

In acute hepatic congestion: • Central vein and sinusoids are distended

with blood• Central hepatocyte degeneration• The periportal hepatocytes - may only

develop fatty change.

CVC liver -- MicroscopyCVC liver -- Microscopy

CVC - Liver

Centrilobular necrosis - causesCentrilobular necrosis - causes

NOTE: Because the central portion of the hepatic lobule is the last to receive blood, centrilobular necrosis can also occur whenever there is reduced hepatic blood flow (including shock from any cause); there need not be previous hepatic congestion.

CVC LungCVC Lung

Pulmonary edema

• The cut surfaces of hyperemic • tissues are hemorrhagic and wet

CVC Lung - GrossCVC Lung - Gross

Acute pulmonary congestion: • alveolar capillaries engorged with

blood• alveolar septal edema and/or • focal intraalveolar hemorrhage

CVC Lung - CVC Lung - Microscopic

Chronic pulmonary congestion: • the septa are thickened and fibrotic• the alveolar spaces may contain

numerous hemosiderin-laden macrophages (heart failure cells).

CVC Lung - CVC Lung - Microscopic

Pulmonary edema with a few extravasated RBCs

Heart failure cells

CVC – Lung [ Perl’s stain ]

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